Mill for reducing paints, colors, and pigments



March 21, 1933- J. R. TORRANCE 1,902, 0 I

MILL FOR REDUCING PAINTS, COLORS. AND PIGMENTS Filed Dec. 21, 1928 3 Sheets-Sheet l vm/z/vmq J55) Ibrmmce 5y W m,

March-21 1933; J. R. TORRIANCE Y 1,902,680

MILL FOR REDUCING PAINTS, COLORS, AND PIGMENTS I Filed Dec. 21, 1928 3 Sheets-Sheet 2 FIG. 2.

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J. R. TORRANCE MILL FOR REDUCING PAINTS, COLORS. AND PIGMENTS 3 Sheets-Sheet 3 Filed Dec. 21. 1928 Y flmwme "T011018. Tbrrance' Patented Mar. 21, 1933 UNITED STATES PATENT OFFICE JOHN ROWLAND TORRANOE, E BITTON, ENGLAND I MII |L FOR REDUCING PAINTS, COL0 1tS,A1\TD PIGMENTS Application filed December 21, 1928, Serial No. 327,704, and in Great Britain January 3, 1928.

This invention relates to improvements in roller mills in which the grinding takes place between rollers having different peripheral speeds.

An object of the present invention is to provide a mill which is'suitable for grinding pastes and semi-pastes as distinguished from liquids and semi-liquids.

According to the present invention there is provided a mill in which the grinding takes place between rollers having different peripheral speeds, comprising a high-speed roll and a plurality of low-speedrolls, the high peripheryspeed rollbeing common to all the grinding nips, so that at all the grinding nips the material passes between the common high periphery speed roll and one or the other of the low periphery speed rolls.

By the present invention there is provided a mill which has one high speed running roll mating with two or more low speed running rolls.

The accompanying drawings show layouts of mills having one fast running roll and two slow running rolls. It is to he understood these forms are shown merely as examples and that the invention is not limited to these particular constructions.

In the drawings Fig. 1 is a diagrammatic view of one form of mill, while Figs. 2 and 3 are respectively, front and part sectional side views of a similar type of mill with a variant gear, and Fig. 4 is a plan view of the gear box with its top removed.

Referring to Fig. 1, the high-speed roll is designated by the reference numeral 1 and the low-speed rolls by 2 and 3. V

The feed of the material is supplied at the upper V 4, and the delivery from the V 5.

A scraper 6 or the equivalent effects a directional controlled removal of the nraterial from the high speed roll 1. A scraper 7 may be applied to the low speed roll 3 for ofl fecting a directional controlled removal of the material from this roll. This scraper 7 may be in the form of, or combined with, a tray onto which the material from the scrape 6 is deflected. I I I Any material at the delivery side of the roll spindle 27.

first grinding nip which may be thrown off the high-speed roll will fall on to theslow roll 3 and be carried thereon to the second grinding nip. y

In some cases a scraper 8 may be placed on the low-speed r0112 adjacent the grinding n1 t The material is fed to the first grinding nip in any suitable way,for example, a feedhopper maybe placed overthe grinding nip between the rolls 1 and 2. Y i

The rolls are driven from 'a-counter'shaft 17 through gearing 10, 11, 12, 13, 14, 15' and 16. The fast roll is driven from the counter shaft 17 by equal sized'wheels 11 and 10. The slow rolls are driven by speed decreasing wheel-trains 12 to 16. The gearing may be mounted in a gear box similar to that shown in connection with Figs. 2, 3 and 4. With this gearing the high-speed roll 1 has a speed of R. P. M., and the low-speed rolls a speed of 20 R. P. M. This differential is suitable for stifli' pastes.

In the construction illustrated by Figs. 2, 3, and 4, 1 isthe high-speed roll,"2 and 3 the low-speed rolls. 7 is the scraper in the form of a tray having'converging: sides 18;

19is a feed hopper. 20 is an adjusting device for setting the position of the roll 2 with relation to the roll 1, and 21 is a similar device for the'roll 3. 22'is the framework of the mill. v

The drive of the rolls is arranged in the following manner. 23 is a countershaft. which runs at the same speed as the fast roll 1. A pinion 24 on 23 drives an intermediate gear wheel 25' on a fixed shaft 29, and the wheel 25 drives a gear wheel26 on the fast Mounted with the intermediate gear wheel 25 is a pinion'wheel 28. i The wheel 25 may be keyed upon the neck of the pinion 28 so thatlthe pair revolve together upon the fixed intermediate shaft 29. Or the wheels 25 and 28 may be keyed to the shaft 29 which shaft then rotates. 1

The wheel 28 is geared with a wheel 30 which is mounted upon the neck. of a pinion 31, which pinion 31 isof .thesamesize as the pi on. v The Whee s 0 e ds. a e he, 1

' l '10 -With both arrangements of gearing shown,

the position of the gear centres of the drive for the high periphery speed roll are fixed,

that is to say the gear centres do not change,

as the position of the centre of the high speed roll does not move, and the two low periphery speed rolls being adjustable towards and from the high periphery speed roll the gears on these rolls can run over the driving I pinion or pinions. These arrangements give, lbvvhat may be termed, a gear which is always self-adjusting, in that it is never necessary to alter or re-adjust the position of the gear centres when the rolls are adjusted to a different setting or to take up wear.

It is'not possible to lay down precise variations of differentiation in periphery speeds as so much depends upon the nature of the materials to bertreated, but the speeds for any given material suited for the treatment 9 are readily determinable by the craftsman. Actual tests that have been made show a very high efiiciency for the present mill.

At one test, five and one half hundredweights of golden ochre paste were ground into-a superior finish in one and a half hours. A triple roller mill can deal with live hundredweights of this material in eight hours. i Y At another test with Prussian blue paste, consisting of equal parts of Prussion blue and Barytes the quantity ground on the present mill in less than three hours was equal to the quantity ground on a triple roller mill in two days, and the ground product was better. 1

Both mills were fitted with rolls of the same size, namely, thirty inches long and fifteen inches in diameter.

' The mill is applicable for reducing paints, colors, pigments, pastes, powders, cocoa,

chocolate, etc. r Y I What I claim is 1 1. A'roller mill of thecharacter described for grinding pastes and semi-pastes, comprising a high periphery speed roll mounted in fixed bearings so as to prevent any oscillation of the roll due to its speed, two low periphery speed rolls, one located beneath the high periphery speed roll, and the other located at the back of said high periphery speed roll, said high periphery speed roll mating with said low periphery speed rolls to form the grinding nips and serving to con- -vey the material from one grinding nip to the next, means for adjustingthe bearings of the low periphery speed rollsin relation to the fixed high periphery speed roll, a driving shaft, a driving Wheel train from said shaft to said high speed roll, a speed decreasing driving wheel train from said shaft to said low speed rolls, a feed hopper from which the material is supplied to the first grinding nip, and a scraper on thehigh periphery speed roll at the front of the mill.

2. A roller mill of the character described for grinding pastes and semi-pastes, comprising a high periphery speed roll mounted in fixed bearings so as to prevent any oscillation of the roll due to. its, speed, a plurality of low periphery speed rolls mounted in spring urged bearings and mating with the high periphery speed rolls at spaced points to provide a succession of grinding.nips,said high periphery speed roll being common to all grinding nips and serving to convey the material from one grinding nip to the next, a driving shaft, a driving wheel train from said shaft to said high periphery speed roll, a speed decreasing driving wheel trainfrom said shaft to said low speed rolls, and a scraper located on the high periphery speed roll adjacent the last nip to remove the material therefrom to a delivery station.

In testimony whereof, I afiix my signature.

JOHN ROWLAND TORRANCE. 

